1. Field of the Invention
The subject invention generally pertains to door hinges and more specifically to a hinge that can extend to provide the door with a greater range of motion.
2. Description of Related Art
Factories, warehouses and other industrial buildings often include two-way swinging doors with double-acting hinges that allow traffic to push the door open in either direction. The hinges often include some type of spring or cam mechanism that automatically returns the door to its central closed position.
For example, the weight of the door may be supported by a cam surface having a valley, wherein a cam follower (that supports the weight of the door) settles into the valley as the door closes. In other words, the cam follower settling into the valley is what closes the door. When the door opens, the cam follower rises out of the valley, which raises the door. To allow the door to rise, there needs to be a gap or some vertical clearance between the upper edge of the door and the head jamb of the doorframe. Since the size of the gap varies as the door swings, such a gap may be difficult to seal.
Regardless of whether a two-way door closes by a spring or cam mechanism, such doors can usually only swing 90-degrees in either direction from its closed position. Attempting to swing the door beyond that often forces the door up against the edge of the wall that holds the door hinges. This is particularly true when the thickness of the wall is wider than the hinge. Since the part of the door that hits the edge of the wall tends to be rather close to the hinged edge of the door, and the opening force is often directed more toward the distal or outer edge of the door, the resulting leverage or mechanical advantage often creates a tremendous prying force that can damage the door and its hinges.
A common scenario, for example, is a forklift truck driving through the doorway with the door hinges to the right of the truck. After passing through the doorway, the forklift immediately turns to the right. If the forklift turns too soon, the forklift may catch the distal edge of the open door and force the door to pivot well beyond its limit.
In some embodiments, a flexible elongate member held in tensions holds a pivotal door up against an anchor attached to a doorjamb of a doorway.
In some embodiments, a door pivots about a pivot point to swing through a range of pivotal positions. Subsequently, the door can move away from the pivot point to move through a range of extended positions.
In some embodiments, the door can swing open in either direction.
In some embodiments, an adjustment can vary the tension in the flexible elongate member.
In some embodiments, a resilient member places the flexible elongate member in tension.
In some embodiments, a door includes a cavity that contains some of the flexible elongate member.
In some embodiments, the weight of the door is supported by a pad that rests directly on the floor.
In some embodiments, a rotatable element couples a flexible elongate member to an anchor that is attached to a doorjamb.
In some embodiments, the flexible elongate member is a chain.
In some embodiments, the flexible elongate member is a strap.
In some embodiments, the flexible elongate member is a cable.
In some embodiments, a wear pad provides wear protection between the flexible elongate member and an edge of the door.
In some embodiments, a door experiences a restorative closing force that increases abruptly as the door moves from a first range of pivotal positions to an extended range of positions.